Automatic self-closing valve



AUTOMATIC SELF CLOSING VALVE Original Filed J 26. 1926 I other change ofHow conditions,

Patented May 31, 1927.

owniv ALFREDPRICE, or Zimmerman;swarm).

,; AUTOMATIC snnr-cnosrne van vii Original application filed'June 26,1926, Serial No. 11-3352, an

and this application filcd'De-cember 10, 1926 Seria1 '1\To.153,'906.

V This invention relates to an automatic self-closing valve to serveinter alia' as an accident valve in a water main or in a water powerpenstock as a'precaution against pipe bursts, or in any hydraulic systemWhere automatic closing is required on occasion of a given excess of therate of flow or any such, for example, as reversal of flowfThis'application is a division of application, Serial Number118,852,filed June26, 1926.

An object of the .invention is to provide such a valve which offers theminimum resistance to the normal flow and which will close withcertainty on change of the conditions o'f'flow without dependence on theoperation of paddles, trip gear or actuating weights, oron the openingof cocks to bydraulic cylinders or on any mechanicalmovements,-eliminating risk of failure to function due to sticking orbreaking of me clianical parts or to errors of adjustment-a risk whichmustb'e reckoned within view of the extreme rarity of'the occasions onwhich -operation of the valve is required and ofthe impossibility oftesting it -under such conditions as arise during an accident.

In theaccompanying drawings Fig. l is a vertical section illustratingdiagrammatically an automatic self-closing valve according to theinvention; Fig. 2 vis a fragmentary section on the hneII-II of Fig.1; F1gs. 3 and 4 are sections to a smaller scale, showing modifiedconstructions of the valve proper.

is constituted As shown, the valve proper as aplunger l whichisslidablefwithin a stationary structure comprising annuli 2, 3 castintegrahrespectively, with-the sections 4, 5 of the valve chest, and anannulus 6 in terpoeed between the'annuli'2,.3 and coaxial therewith. Theplunger land annular structure'2, 3, 6 present a stream-lined-bodyinterposed in theconducting channel immediatelyin advance of a throat 8or zone of less cross-sectional area than the main channel;

A's'will be understood, when flow takes place the back of'theplunger 1is subject-to the full pressure in themain 7 andthe front of the plungeris subject to-the lower pressure in the throat 8.

The front of the plunger 1 is fitted with a ring 9 in axial registerwith a seat ring l fitted to the section of the valve chest.

Integral with the plunger l-is a balancing piston 11 slidable within'theannulus 6 and towards closing controlled. Each valve 24 1 GreatBritain zruaeia'r, 1925. Divided 12 .iszconnec'tcd with the throat'8bywa-y'of a valved pipe 14, and. the compartment 13=is connected with themain 7 way of a valved pipe 15.

The several'areas of the plunger ends and balancing pistons the totalfluid valve is greater-than the total fluid pressure tending to open it,that is", the sum of the forces acting onthe back of the plunger 1 andon the baekof the -piston 11. is greater are so proportioned thatthanfthe sum of the forces acting on the front of'the V plunger 1 and onthe -front of the piston 11, the-plunger being supported posing forces;

To hold the plunger 1 stable for any re is connected to theback of theplunger 1 by cranks '19 and links 20, the counterweights pressuretendingto close the approximatelydn {equilibrium by' these 013-secured-to a spindle 18 which is; I 'gournalled in the chest section 4;and which 16 being adjustable to-balance the. closing effort at theparticular velocity desired.

The arrangement ofthe piston ll'inthe structure 2, 3', 6 provides a i tocushion the closing movement of the plunger 1, 'so that the possibilityof too rapid closure of the valve is precluded.

A. throttle member 21 connected by a crank 22 and adjustable link 23 toeither lever 17 .is adapted to constr-ict the passage afforded by thepipe -asthe 'plunger l moves position whereby to in crease gradually thecushioning effect.

Located in; the

pipes 14 and l5, respecdashpotserving.

ti vely,are exhaust valves 24' and 25 "by manipulation ofwhic'h the mainvalve may be to seaton either of two se'ats26 or 27, the

or 25 is adapted lam seat 26 openinginto an exhaust branch 28 and theseat-'27z-opening into the part of the, 1 011x15" leading to the; throat8 or main-7. Vith this arrangement, by lifting the valve 25 frointheseat 26 w-ater under pressurein the compartment 13 fis releasecl toexhaust whereupon the main valve closes.

The main valve maybe reopened by re storing the valve 25 onto engagementwith its seat 26 and lifting-the valve-24 from'its closure, the netclosing 7 and undesirably rapid closing plunger movable in said lid andin said Zone,'an'

shown connected to the The pipe 14 is of the seat ring valve chestupstream water in the main 7 is brought to rest, due totheclosing of thevalve, the pressures on the twosides of the balancing piston 11 and onthe back of the plunger approach the static pressure due to the head orwater upstream of the valve, that is, the various pressures areequalizing, and, at the instant of force is that due to the staticpressure acting on an area equal to that enclosed within the seat ring10. This powerful closing force, is, of course, built up very graduallyand only comes into action at the last moment to force the valve on itsseat. Nh-erevery high headexists, is likely to result, the pipe 14 isconnected to the valve chest desirably on thedownstream side 0 the ring10. e V e In the modified construction shown 1n Fig. 3 the back end ofthe plunger 1 is 0 smaller diameter than the front end, such aconstruction being suitable for'installation in a main in which thenormal stream velocity is high and consequently the reaction pressure onthe back of the plunger of considerable magnitude. r 1 I The modifiedconstruction of valve shown in Fig.- l is suitable tor-installation in amain in which the normal stream velocity is low, the back end of theplunger 1 being of I greater diameter than the front end,

, lVhat Iclaim is g I V r ,1. An automatic self-closing valve,comprising, in combination with a main conducting channel for fluidhaving a zone of less cross-sectional area than that of the remainderol' the channel,

vicinity of said zone, said plunger having its closing movement in thedirection towards said zone, said plunger exposed at its opposite endsto the pressures 1n said ma n chanrounding said plunger and forming withsaid-plunger a structure of stream-line formvspaced from the'internalwall of said channel, a balancing p ston. movable with said;

plunger, between said; plunger and said annular body, said zone beingsubject tothe pressure in said main channel andthe other side ofsaidpiston, being subject to the pressure in said zone, and means servingnormally to hold said plunger stable m open position but adapted to beovercome on predetermined variation of the diilerential pressure between{the mainfchannel andsa d zone occasioned 10. Vvith this arrangement asthe column of" less cross-sectional a valveiorming channel in theannular body surt the side ofsaid piston nearest to j mit unaidedautomatic closing movement of said plunger. i i

2; An automatic self-closing valve, comprising,.' in combination with amain conducting channel ior fluid having a zone of less cross-sectionalarea than that of the remainder of the channel, valve-forming plungermovable in .said channel in the vicinity of said zone, said plungerhaving its closing movement in the direction towards said zone, saidplunger exposed at its opposite ends toethepressures insaid' mainchannel and in said zone, an annular body surrounding said plunger andspaced from the 'aternal wall of said channel, a balancing pistonmovable with said plunger and hearing on said annular body, connectionsbetween the opposite sides of said piston and the main channel andchannel and one side of the piston, said throttle device beingoperatively connected to said plunger, and means serving normally tohold said plunger stable in open position but adapted to be overcome onpredetermined variation or the differential pressure between the mainchanneland said zone occasioned by change of the. conditions of flow, topermit unaided automatic closing movement of said plunger; j 8. Anautomatic self-closing valve, comprising, in combination with a mainconductingchannel for fluid having, a zone of area than that of theremainder of the channel, a valve-forming plunger movablefiin' saidchannel 7 in the vicinity of said zone, said plunger having its closingmovementjin thedirection towards said zone, said plunger exposed itsopposite endsto the pressures in said main channel andin saidfzone, anannularbody surrounding plunger stable in open position but adapted tobe. overcome on predetermined variation or the diil'erential" pressurebetween the main channel and said; zone occasionedby change of theconditions of flow,-to .permit'unaided automatic clos ng movement ofsaidplunger.

In testimony whereof I have signed my name tothisfspeclficatiomx I Isaid plunger, and spaced .from the internalwalloi'i sa d channel, abalancing the main channel and. said so zone, a throttle device in theconnectiontbetween sald main llO 4 K fownNagPRroEf

